我在EasyARM2104上调试UCOSII时发现了个问题。
   单个任务在该系统下都能正常运行。一旦同时运行多个任务就不行了。
请高手分析一下是什么原因？
附原代码

#include "config.h"

#define  TASK_STK_SIZE  128     

#define SPI_CS   0x00000100 //P0.8
#define SPI_DATA  0x00000040 //P0.6
#define SPI_CLK  0x00000010 //P0.4
#define BEEP  0x00000080 //P0.7
#define SPI_IOCON 0x00003dd0 

OS_STK        Task1Stk[TASK_STK_SIZE];   
OS_STK        Task2Stk[TASK_STK_SIZE];      
OS_STK        Task3Stk[TASK_STK_SIZE];      
OS_STK        TaskStartStk[TASK_STK_SIZE]; 

void  Task1(void *data);            
void  Task2(void *data);      
void  Task3(void *data);      
void  TaskStart(void *data);   

int main (void)
{
    OSInit(); 
    OSTaskCreate(TaskStart, (void *)0, &TaskStartStk[TASK_STK_SIZE - 1], 0);
    OSStart(); 
    return 0;                                         
}

void  TaskStart (void *pdata)
{
#if OS_CRITICAL_METHOD == 3      
    OS_CPU_SR  cpu_sr;
#endif
      pdata = pdata;              
 PINSEL0 =0x00000000;
 PINSEL1 =0x00000000;
 IODIR = SPI_IOCON;
   
     TargetInit();       
   
  OSTaskCreate(Task1, (void *)0, &Task1Stk[TASK_STK_SIZE - 1], 1);
  OSTaskCreate(Task2, (void *)0, &Task2Stk[TASK_STK_SIZE - 1], 2);
  OSTaskCreate(Task3, (void *)0, &Task2Stk[TASK_STK_SIZE - 1], 3);  
 OSTaskDel(0);  
}

void  Task1 (void *pdata)
{ 
 uint8 i;
 pdata = pdata; 

    for (;;) {
 for(i=0;i<16;i++)
 {   
 IOSET = 0x00003c00;
 IOCLR = i<<10;
 OSTimeDlyHMSM(0, 0, 1, 0);         
        }
     }
}

void  Task2 (void *pdata)
{ 
 pdata = pdata; 
    for (;;) {
   
 IOSET =BEEP;
        OSTimeDlyHMSM(0, 0, 0, 200);    
 IOCLR =BEEP;
        OSTimeDlyHMSM(0, 0, 0, 200);   
    }
}

///以下为Task3:数码管显示数字0~9//
void HC595_SendDat(uint8 dat)
{
 uint8 i;
 
 IOCLR = SPI_CS;
 for(i=0;i<8;i++)
 {
 IOCLR = SPI_CLK;
 if((dat& 0x80)!=0) IOSET=SPI_DATA;
 else IOCLR = SPI_DATA;
 dat<<=1;
 IOSET = SPI_CLK; 
 }
 IOSET = SPI_CS;
}

void  Task3 (void *pdata)
{ 
const uint8 DISP_TAB[16]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e}; 
uint8 i;
pdata = pdata; 
   for (;;)
    {
 for(i=0;i<10;i++)
 {
 HC595_SendDat(DISP_TAB[i]);
 OSTimeDlyHMSM(0, 0, 1, 0);
 }
    }
}

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